where \(\rho \)  is the total energy density. This \(F(R)\)  gravity regime was used to explain late time cosmic acceleration as an alternative to dark energy in [1]}. The action prompts one towards the notion that very tiny corrections to the usual Einstein Hilbert in the form of \(R^{n}\)  with \(n<0\)  can produce cosmic acceleration. As corrections of the form \(R^n\)  with \(n>0\)  can lead to inflation in the early universe [2]}, the authors in [1]} proposed a purely garvitational paradigm through (5) to explain both the early and late time accelerations of the universe. Explaining the current epoch of the universe through such a modified gravity model would in principle eliminate the need of dark energy and hence, its an interesting scenario to consider w-singularities in as well.
